The Low Carbon Economy Ltd

Waitrose sends waste to anaerobic digester

Anaerobic digestion waste plants which produce biogas to burn in power plants could play a part in how supermarkets dispose of food waste in the future.

A trial by five Waitrose branches involves sending their food waste, as well as other biodegradable products, to Biogen's Bedford anaerobic digestion plant.

Recycling expert Cawleys collects the waste from the branches and takes it to the plant, where waste is stored in massive tanks with bacteria that help break it down into biogas  carbon dioxide and methane.

The operation makes greenhouse gas savings because the waste would decompose in a landfill and leak carbon dioxide and methane into the environment. The gas created in anaerobic digesters is burned to generate power  a process which would otherwise require gas to be bought from another source.

Waitrose Recycling Waste Manager Arthur Sayer told FoodBev: "Anaerobic digestion has been operating in other European countries, such as Germany, for decades, so we thought it was worth trying out on a commercial scale for our supermarkets. So far, the signs are really positive, and this looks to be a sustainable way of eliminating the need to send waste food to landfill."

Environment minister Joan Ruddock told the Times that an anaerobic digestion plant could fit into any industrial estate in the country.